So someone wants me to edit a project, and the footage they gave me are MTS files....I've never even heard of this filetype. Vegas doesn't accept it, and I can't figure out a good way to convert it without losing lots of quality or getting a crapload of dropped frames. Has anyone had to work with this kind of file before? Any ideas?

I'm tired, so I didn't think of this before. You might try DSS2() in avisynth, which is what I currently use for Blu-ray (m2ts).I do not know if this works for it, but if it does your best quality option is DGDecNV.

Assuming it is an AVC video, DGDecNV is your best chance. If you do not have a cuda gpu, you could try DGAVCDecDi. If you don't want to buy either, you're out of luck, as it seems that ffmpeg/libav won't work with it, so the old DGAVCDec based on ffmpeg is not a solution either.

Which is quite odd to be honest. Can you post a mediainfo report in its text mode? I would like to know format and stuff.

Yeah, that looks like bd-tier video streams. Those tend to hurf with ffms2 from time to time for no known reason, even when remuxing. You should really try DGDecNV or DGAVCDecDi if you want an easy way out.Otherwise, another thing you might want to try could be transcoding to a lossless format with mplayer2-vo-lavc and see if it works.Something like

The reason it derps in FFMS2 is vaguely known last I checked. Certainly in lavf at least.

MTS is the AVCHD subset of the extended M2TS format. It has the same general format as a BD or ISDB-S transport stream (ie standard MPEG-TS with 4-byte timecodes at the start) but a stricter set of bitrates and codecs. You find it on camcorders and in the output of some video programs. I'm quite surprised Vegas doesn't like it as it's relatively common and Vegas isn't exactly a pro tool but as written above, DG* is the current way to handle it.

Out of interest, does FFMS2 work fine if you tell it to disable seeking? Render a lossless and it should be ok. Note that mplayer2 uses lavf and is quite possibly even more broken than FFMS2 is; probably best to avoid that.